Parental deprivation in early childhood impacts gene expression on brain development as a lifelong effect

Abstract Early life experiences, such as parental loss, neglect, and child abuse, are well-established risk factors for neurological disorders later in life, including depression, anxiety disorders, and post-traumatic stress disorder. However, the molecular mechanisms underlying the impact of adverse childhood experiences on neurophysiological systems throughout life remain incompletely understood. Common marmosets, which are non-human primates, typically give birth to 2–4 offspring, but only two usually survive. Therefore, human hand-rearing is employed to ensure the survival of the offspring. However, marmosets that are raised by humans often exhibit behavioral abnormalities, including abnormal vocalizations, excessive attachment to the caretaker, and aggressive behavior. Hence, our study aimed to investigate the hypothesis that human hand-rearing induces alterations in gene expression within the brains of infant marmosets, and that these changes persist into adulthood and are associated with behavioral abnormalities. Our analyses revealed consistent alterations in a subset of genes, including those related to neurodevelopmental diseases, across different developmental stages, indicating their continuous susceptibility to the effects of early parental deprivation. These findings highlight the dynamic nature of gene expression in response to early life experiences and suggest that the impact of early parental deprivation on gene expression may vary across different stages of development.